Model 8360/8382/8383/8388 VELOCICALC Plus Air Velocity Meters Operation and Service Manual

September 1998

P/N 1980253 Rev C

Model 8360/8382/8383/8388 VELOCICALC Plus Air Velocity Meters Operation and Service Manual

September 1998

P/N 1980253 Rev C

SHIP TO: MAIL TO: TSI Incorporated TSI Incorporated 500 Cardigan Road P.O. Box 64394 Shoreview, MN 55126-3996 St. Paul, MN 55164-0394 USA USA

U.S. INTERNATIONAL Sales and Customer Service: Sales and Customer Service: (800) 777-8356 / (651) 490-2711 (1) 651 490-2711 Fax: Fax: (651) 490-2874 (1) 651 490-2874

Copyright TSI Incorporated/September 1996/All rights reserved. Address TSI Incorporated/P.O. Box 64394/St. Paul, MN 55164/USA Fax No. (651) 490-2874

LIMITATION OF WARRANTY AND LIABILITY. Seller warrants that this product, under normal use and service as described in the operator's manual, shall be free from defects in workmanship and material for a period of twenty-four (24) months, or the length of time specified in operator's manual, from the date of shipment to the customer. This limited warranty is subject to the following exclusions: a. Batteries and certain other components when indicated in specifications are warranted for a period of 90

days from the date of shipment to the customer. b. With respect to any repair services rendered, Seller warrants that the parts repaired or replaced will be

free from defects in workmanship and material, under normal use, for a period of 90 days from the date of shipment to the customer.

c. Seller does not provide any warranty on finished goods manufactured by others. Only the original manufacturer's warranty applies.

d. Unless specifically authorized in a separate writing by Seller, Seller makes no warranty with respect to, and shall have no liability in connection with, any goods which are incorporated into other products or equipment by the Buyer. All goods returned under warranty shall be at the Buyer’s risk of loss, Seller’s factory prepaid, and will be returned at Seller’s risk of loss, Buyer’s factory prepaid.

The foregoing is IN LIEU OF all other warranties and is subject to the conditions and LIMITATIONS stated herein. NO OTHER EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR PARTICULAR PURPOSE OR MERCHANTABILITY IS MADE.

THE EXCLUSIVE REMEDY OF THE USER OR PURCHASER, AND THE LIMIT OF THE LIABILITY OF SELLER FOR ANY AND ALL LOSSES, INJURIES, OR DAMAGES IN CONNECTION WITH THIS PRODUCT (INCLUDING CLAIMS BASED ON CONTRACT, NEGLIGENCE, STRICT LIABILITY, OTHER TORT, OR OTHERWISE) SHALL BE THE RETURN OF THE PRODUCT TO THE FACTORY OR DESIGNATED LOCATION AND THE REFUND OF THE PURCHASE PRICE, OR, AT THE OPTION OF SELLER, THE REPAIR OR REPLACEMENT OF THE PRODUCT. IN NO EVENT SHALL SELLER BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTlAL DAMAGES. SELLER SHALL NOT BE RESPONSIBLE FOR INSTALLATION, DISMANTLING, REASSEMBLY OR REINSTALLATION COSTS OR CHARGES. NO ACTION, REGARDLESS OF FORM, MAY BE BROUGHT AGAINST THE SELLER MORE THAN ONE YEAR AFTER THE CAUSE OF ACTION HAS ACCRUED.

The purchaser and all users are deemed to have accepted the terms of this LIMITATION OF WARRANTY AND LIABILITY, which contains the complete and exclusive limited warranty of Seller. This LIMITATION OF WARRANTY AND LIABILITY may not be amended or modified nor may any of its terms be waived except by a writing signed by an authorized representative of Seller.

Service Policy Knowing that inoperative or defective instruments are as detrimental to TSI as they are to our customers, our service policy is designed to give prompt attention to any problems. If any malfunction is discovered, please contact your nearest sales office or representative, or call TSI's Customer Service department at (800) 777-8356 (USA) and (1) 651 490-2711 :(International).

i

CONTENTS Chapters 1 Unpacking and Parts Identification...................................1

List of Components ...............................................................1

2 Setting-Up ............................................................................3 Supplying Power to the VELOCICALC....................................3 Installing the Batteries........................................................3 Selecting the Display Units ...................................................3 Using the Telescoping Probe...............................................3 Extending the Probe .........................................................4 Retracting the Probe..........................................................4

3 Operation .............................................................................5 Overview ...............................................................................5 Keypad Functions .................................................................5 ON/OFF Switch.....................................................................5 Measuring Velocity................................................................5 Measuring Temperature ......................................................5 Measuring Pressure.............................................................6 Zeroing Pressure ...............................................................6 Measuring Humidity (Model 8360 and 8388 Only) ...............6 Dew Point Function (Model 8360 and 8388 Only)................6 Flow Rate Function...............................................................7 Flow Rate (Calculated Using Velocity and Duct Area) .........7 Entering Shape and Size ...................................................7 Flow Rate (Calculated Using Pressure and Flow Factor, Models 8382, 8383, and 8388 Only) ....................................8 Entering Flow Factor..........................................................8 Time Constant Function........................................................9 Using the Clear, Store and Average Functions ....................9 Store Function....................................................................9 Average Function.............................................................10 Clear Function..................................................................10 Printer Port..........................................................................10

ii

4 Maintenance ..................................................................... 11 Probe Tip............................................................................ 11 Recalibration ...................................................................... 11 Cases ................................................................................. 11 Storage............................................................................... 11

5 Troubleshooting............................................................... 13 Appendices A Specifications ..................................................................... 15 B DIP Switch Settings............................................................ 17 C Standard Velocity vs. Actual Velocity................................. 19 Available Application Notes • Constant Temperature Thermal Anemometry Theory .....#TI-105 • Traversing a Duct to Determine Average

Air Velocity or Volume ......................................................#TI-106 • Applications Using the VELOCICALC Plus to

Measure Pressure ............................................................#TI-107 • VELOCICALC Serial Interface Connections ........................#TI-108 To obtain any of the listed Application Notes contact TSI at U.S. (800) 777-8356/(651) 490-2711 Fax: (651) 490-2874 International (1) 651-490-2711 Fax: (1) 651-490-2874

1

Chapter 1 Unpacking and Parts Identification Carefully unpack the instrument and accessories from the shipping container. Check the individual parts against the list of components in Table 1. If any are missing or damaged, notify TSI or your local distributor immediately. Table 1. List of components Qty Item Description Part/model 1 Model 8360 VELOCICALC Plus or 8360 Model 8382 VELOCICALC Plus or 8382 Model 8383 VELOCICALC Plus (Articulating Probe) or 8383 Model 8388 VELOCICALC Plus 8388 1 Carrying Case 800277 4 AA Alkaline batteries 1208013 1 AC Adapter (Optional)

115 V, NEMA-5 230 V, European, CEE 7/16 230 V, Great Britain 240 V, Australian

2613033 2613078 800169 2613105

1 Operation and Service Manual 1980253 1 Static pressure tip 3002017 8 ft. Rubber tubing 801039

Chapter 1 2

Parts Identification

3

2

4

1

6

5

Figure 1-1 VELOCICALC

1. On/Off Switch 4. Probe Mounting Clips 2. Display 5. Pressure Measurement Ports 3. Function Keys 6. Battery Access Cover

3

Chapter 2 Setting-Up Supplying Power to the VELOCICALC The VELOCICALC can be powered in one of two ways: four size AA batteries or the optional AC Adapter.

Installing the Batteries Insert four AA batteries as indicated by the diagram located on the inside of the battery compartment. TSI ships the unit with alkaline batteries. The VELOCICALC is designed to operate with either alkaline or NiCd rechargeable batteries. Carbon-zinc batteries are not recommended because of the danger of battery acid leakage. Table 2-1 Typical Battery Life at 20°C

Air Velocity Alkaline NiCd (ft/min) (m/s) (hrs) (hrs)

100 0.5 7.0 5.0 1000 5.0 4.4 3.5 9000 45.0 2.4 2.4

Using the AC Adapter When using the AC adapter, the batteries (if installed) will be bypassed. The AC adapter is not a battery charger.

Selecting the Display Units The VELOCICALC is capable of displaying the measured values in several different measurement units. The choices of measurement units are shown in Table 2-2. Table 2-2. Choices of Measurement Units

Velocity Temperature/ Dew Point

Flow Rate Pressure

ft/min °F ft3/min in. H2O m/s °C m3/hr mm Hg

l/s kPa To change the display units on your VELOCICALC, refer to Appendix B, DIP Switch Settings. Using The Telescoping Probe The telescoping probe, mounted on the side of the VELOCICALC, contains the velocity, temperature, and humidity sensors (humidity sensor, Model 8360 and 8388 only). The probe is shipped pointing downward in the stowed position. The probe can be used either mounted on the VELOCICALC

Chapter 2 4

or held in your hand. If the probe is to be used mounted to the VELOCICALC, remove the probe from its stowed position, turn it 180°, and reinstall (pointing upward) in the probe mounting brackets.

Extending The Probe To extend the probe, hold the handle in one hand while pulling on the probe tip with the other hand. Do not hold the cable while extending the probe as this prevents the probe from moving. Retracting The Probe To retract the probe, hold the handle in one hand while pushing on the probe tip with the other hand. If you feel the probe antenna binding, pull gently on the probe cable until the smallest antenna section is retracted. Collapse the rest of the antenna by pressing the probe tip.

When using the probe, make sure the sensor window is fully exposed and the red orientation dot is facing upstream.

5

Chapter 3 Operation Overview The Model 8360/8382/8383/8388 VELOCICALC PLUS measures air velocity, temperature, differential pressure, and calculates volumetric flow rates. In addition the 8360/8388 VELOCICALC PLUS measures relative humidity and calculates dew point from the temperature and relative humidity readings. The Model 8383 VELOCICALC PLUS has an articulating probe. The VELOCICALC PLUS can store individual readings and compute the average of these readings. Keypad Functions When pressing the keys on the front panel, the VELOCICALC will beep to confirm the function. If you press a key and the VELOCICALC does not beep, then the VELOCICALC does not allow that function during the selected mode. The beep function can be disabled by changing the internal DIP switch (refer to Appendix B). ON/OFF Switch Slide the switch upward to the ON position. The power switch is marked in the international symbols '|' for on and 'O' for off. When the instrument is first turned on it goes through a preprogrammed power-up sequence that includes an internal self-check. First, all displayable items will appear for a few seconds. If a problem is detected, the display will light ‘CAL’ to indicate that it should be returned for servicing and calibration. When the VELOCICALC completes the internal self-check, it will display the approximate percentage of battery life remaining. This feature is accurate for alkaline batteries only. Measuring Velocity Press the VELOCITY key to display velocity measurements (the VELOCICALC will automatically start in velocity mode). The velocity will be displayed in ft/min or m/s depending on the DIP switch settings (refer to Appendix B). Place the end of the probe in the location where you want to make the measurement. Make sure the sensor window is fully opened and the red orientation dot is facing upstream. Measuring Temperature Press the TEMP key to display air temperature readings. The VELOCICALC will display temperature readings in either degrees Celsius (°C) or degrees Fahrenheit (°F), depending on the DIP switch settings (refer to Appendix B). Allow about 30 seconds for the temperature reading to stabilize after

Chapter 3 6

switching to temperature mode. This is necessary because the velocity sensor is heated during velocity mode, and some heat is conducted down to the temperature sensor. Measuring Pressure Press the PRESSURE key to measure differential pressure. To measure pressure, tubing must be connected to the pressure ports on the top back of the unit. When the pressure source is connected the same way the pressure ports are marked, the meter will display a positive number.

Zeroing Pressure If the zero reading of pressure has drifted, the pressure function can be easily re-zeroed. To reset the zero, make sure that the pressure ports are exposed to the exact same pressure. The easiest way to do this is to remove the pressure hoses and leave both ports exposed to ambient pressure. Press and hold the PRESSURE key down for at least three seconds. The VELOCICALC will give a double beep and the display will show “0 in. H2O” (or whatever units have been selected). When the key is released the display will be re-zeroed.

Measuring Humidity (Model 8360 and 8388 Only) Press the HUMIDITY key to display humidity readings. The readings will be in units of percent relative humidity (%RH). The reading may need time to stabilize if the ambient conditions have recently changed. In order to see if the humidity reading has stabilized, extend the probe and gently wave it back and forth (or place it in a location where there is a sufficient quantity of moving air), while checking the display for an upward or downward trend in the readings. When no particular trend is apparent, the reading has stabilized. Situations that may require time to stabilize the sensor would be when moving the instrument from a cold vehicle or storage place into a heated building. Also, if the end of the probe has been warmed by being handled, it will need to cool to ambient temperature. Another example would be when moving from a location with low humidity to high humidity, or vice versa. Dew Point Function (Model 8360 and 8388 Only) Press the DEW POINT key to display the dew point temperature. The dew point is calculated using the temperature and relative humidity measurements. Because dew point is not measured directly, accuracy of this calculation depends on both ambient temperature and relative humidity. The dew point reading will be most accurate when the relative humidity is 50% and above (and dew point temperature is closer to the actual temperature). It

Operation 7

will be less accurate when the relative humidity is less than 50% (and dew point temperature is farther away from the actual temperature). Flow Rate Function The VELOCICALC’s flow rate function can calculate flow rate using a known area. The Model 8382/8383/8388 VELOCICALC can also calculate flow rate through diffusers by multiplying the square root of the pressure reading by a manufacturer-supplied flow factor. The VELOCICALC displays the volumetric flow rate in ft3/min, m3/hr, or l/s, depending on the DIP switch setting (refer to Appendix B). Flow Rate (Calculated Using Velocity and Duct Area) The flow rate can be calculated for a round, square or rectangular duct. The shape and size of the duct or other area through which the flow will be measured must be entered.

Entering Shape and Size Press the FLOWRATE key to put the VELOCICALC in flow rate mode. The VELOCICALC will prompt the user to enter the shape and size, if this has not been done since the instrument was turned on. The VELOCICALC will request entry of the shape by alternately flashing the circle and rectangle (and pressure units, if DIP switch #6 is ON) on the display. If shape and size have been entered, the VELOCICALC will go directly to displaying flow rate. Press the SHAPE key to select the shape of the area, rectangular (square) or circular, to measure. Each time the SHAPE key is pressed the shape will change back and forth between the circle and rectangle. When the desired shape appears on the display press the ENTER key. This will enter the shape and the VELOCICALC will then ask for the size. Use the LARGER and SMALLER keys to select the size of the flow rate area. For a circular flow shape the VELOCICALC will ask for one size, the diameter of the circular area. Select the size and press ENTER to accept it. For a rectangular area the VELOCICALC will ask for two dimensions. First select the horizontal dimension and press the ENTER key, then select the vertical dimension and press ENTER. To change the shape, press the SHAPE key to select the desired shape. Proceed as above to enter the shape and dimensions. To change the size, hold the LARGER or SMALLER key to enter the new dimensions, then press the ENTER key to accept them.

Chapter 3 8

Flow Rate (Calculated Using Pressure and Flow Factor, Model 8382, 8383, and 8388 Only) This option is available with Model 8382/8383/8388 only when DIP switch #6 is ON (refer to Appendix B). The flow rate through a diffuser is calculated by multiplying a pressure reading by a manufacturer-supplied flow factor. This flow rate measurement method is applicable for diffusers that contain pressure taps designed for this purpose. NOTE: When using this option, make sure that the VELOCICALC pressure measurement units and flow rate measurement units are set using the DIP switches to correspond to those provided by the diffuser manufacturer (refer to Appendix B). If using kPa to do this measurement, flow factors should be entered using Pa, not kPa. If they are set incorrectly, the calculated flow rate will be incorrect. The VELOCICALC will display flow rate and pressure units simultaneously to indicate that the flowrate is being measured from pressure and not from velocity and area. To zero the pressure transducer while in this measurement mode, press and hold the PRESSURE key. The pressure will zero and the VelociCalc will return to flow rate from pressure measurement mode.

Entering Flow Factor Press the FLOWRATE key to put the VELOCICALC in flow rate mode. The VELOCICALC will prompt you to enter the shape, size, or flow factor if this has not been done since the instrument was turned on. The VELOCICALC will alternately flash the circle, rectangle, and pressure units on the display. If shape, size, or flow factor have been entered, the VELOCICALC will go directly to displaying flow rate. Press the SHAPE key to select the pressure-flow rate measurement method. Each time the SHAPE key is pressed the shape will change between the circle, rectangle, and pressure units. When the pressure units appear on the display, press the ENTER key. The VELOCICALC will then ask for the flow factor. The VELOCICALC will display ‘FAct = ‘ and the current flow factor. Use the LARGER and SMALLER keys to select the value of the flow factor and press ENTER to accept it. To change the flow factor, press the SHAPE key to select the pressure units. Proceed as above to enter the value.

Operation 9

Time Constant Function Momentarily press and release the TIME CONSTANT key to view the current time-constant. To change the time-constant, press and hold the key. The available time-constant choices ( 1, 5, 10, 15 and 20 seconds) will sequence on the display. When the desired value is displayed immediately release the key. The VELOCICALC will always reset the time constant to 1 second when turned off. The time-constant is actually an averaging period. The VELOCICALC display is always updated every second, however, the reading displayed is the average reading over the last time-constant period. For example, if the current time-constant is set to 10 seconds, the display will show readings averaged over the previous 10 seconds, updated every second. This is also called a 10 second “moving average.” Using the Clear, Store and Average Functions The VELOCICALC has the ability to compute the average of a number of individual stored readings. Every time the STORE key is pressed, the currently displayed reading is added to a store buffer. When the AVERAGE key is pressed, the readings in the store buffer are divided by the number of stored readings to get the average. The CLEAR key is used to clear out the store buffer in order to start taking a new average.

Store Function Press and hold the STORE key to store the currently displayed measurement. The display will show “STORE” and the number of stored data points that are in memory for about two seconds, and then the recorded value will be displayed until the STORE key is released. The individual stored values can not be recalled. Only the average of the stored values can be recalled. There are five different store buffers: one for both velocity and flow rate from area, one for temperature, one for humidity, one for pressure, and one for dew point. Models 8382, 8383, and 8388 have a sixth storage buffer for flow rate from pressure. You can switch between measuring modes and store data without affecting data stored in the buffer for another measuring mode. You can later return to any mode and add additional values to the already stored values. The flow rate from area function (measures and stores velocity readings, calculates flow rate) and velocity function use the same storage buffer. Measurements made in one mode are added to those made in the other mode.

Chapter 3 10

When using the flow rate from pressure measurement mode, changing the flow factor value will automatically clear the flow rate storage buffer. Average Function Press the AVERAGE key to display the average of the stored values of the current operating mode. The message “AVG” will appear along with a number (between 1 and 255) indicating how many stored values are in the memory buffer. The average value is then displayed for one second. To keep displaying the average value, press and hold the AVERAGE key. Additional values can be stored after the AVERAGE key has been pressed. The next time the AVERAGE key is pressed, the additional values are averaged with those already accumulated. Clear Function Press the CLEAR key to erase the stored value in the buffer of the currently active function. Pushing the CLEAR key in one function will not affect the values stored in other buffers. However, velocity and flow rate from area use the same buffer, so clearing velocity will also clear the flow rate. Flow rate from pressure is not affected by clearing velocity. For example, pushing CLEAR while measuring velocity will not affect the values stored for temperature.

Printer Port While pushing the STORE, AVERAGE or CLEAR key the data is automatically transmitted to the printer port. If the optional Model 8925 Portable Printer is connected the readings will be printed.

11

Chapter 4 Maintenance Probe Tip Periodically inspect the probe tip to ensure that it is clean. Dust and oil deposits on the velocity sensor decrease the accuracy of the VELOCICALC. Caution: The VELOCICALC must be switched off for cleaning. Do not

use high-pressure air, strong solvents, or brushes to clean the sensor tip; damage to the sensors could result.

To remove dust, blow it off with a gentle stream of air or rinse it off with a gentle stream of water. To remove a combination of dust and oil, rinse the probe tip in isopropyl alcohol and then blow it off with a gentle stream of air. Be careful not to get the humidity sensor wet! (The humidity sensor on Models 8360 and 8388 is located at the base of the probe window, just inside the antenna tube.) Also, for the 8383, be careful not to allow water to enter the articulating probe joint. Caution: Never use heat to dry the probe. Permanent damage to the

sensor could result. Recalibration To maintain a high degree of accuracy in your measurements, TSI recommends that you return your instrument for annual recalibration. For a nominal fee, we will recalibrate the unit and return it to you with a certificate of calibration and US National Institute of Standards Technology (NIST) traceability. This 'annual checkup' assures you of consistently accurate readings; it is especially important in applications where strict calibration records must be maintained. Cases If the instrument case or storage case needs cleaning, wipe it off with a soft cloth and isopropyl alcohol or a mild detergent. Never submerge the VELOCICALC. Storage When storing the VELOCICALC for more than a month, it is recommended to remove the batteries. This prevents damage due to battery leakage.

13

Chapter 5 Troubleshooting Table 5 lists the symptoms, possible causes, and recommended solutions for common problems encountered with the VELOCICALC. If your symptom is not listed, or if none of the solutions solves your problem, please contact TSI. Table 5. Troubleshooting the VELOCICALC Symptom Possible Causes Corrective Action No display Unit not switched on Switch on the unit. Low or dead batteries Replace the batteries or

plug in the AC adapter. Dirty battery contacts Clean the battery

contacts. BAT is blinking Batteries are low Replace or recharge

batteries. Display reads "LO BAT"

Low battery charge Replace or recharge batteries.

Wrong AC adapter Replace with the correct AC adapter.

Low AC line voltage Correct the AC line voltage or use batteries.

Dirty battery contacts Clean the battery contacts.

Temperature initially reads high

Temperature sensor is still warm from velocity mode

Allow about 30 seconds before reading temperature.

Display reads "ERR"

You are trying to enter more than 255 readings

Read or record the average; clear the storage register and proceed.

Display reads "CAL"

The VELOCICALC has detected an internal fault

Return to factory for service.

Velocity reading fluctuates badly

The flow is fluctuating Reposition the probe in a less turbulent section of the flow or use a longer time constant.

Display says "OVER"

The velocity, temperature or pressure is too high

Use an alternate measurement method.

14 Chapter 5

Warning! Remove the probe from excess temperature immediately: excessive heat can damage the sensor. The pressure sensor is protected from damage up to 10 psi. (75 kPa or 560 mm Hg) At higher pressures it can burst!

Notice: There is sometimes confusion between dew point temperature and wet-bulb temperature when comparing VELOCICALC humidity readings to sling psychrometer readings. (Dew point temperature and wet bulb temperature are not the same thing.) On the psychometric chart used with a sling psychrometer, dew point temperature is a flat horizontal line, wet bulb temperature is a straight line angling downwards from the left, dry bulb temperature is a straight vertical line and relative humidity is a curved line angling upwards from the left.

15

Appendix A Specifications

Model 8360/8388 VELOCICALC Plus

Models 8382/8383 VELOCICALC Plus

Velocity Measurement Range Accuracy¹

1

30 to 9,999 ft/min (0.15 to 50 m/s) 3% of reading or 3 ft/min (0.02 m/s), whichever is greater

Same Same

Temperature Measurement Range Resolution Accuracy

14 to 140°F (-10 to 60°C) 0.1°F (0.1°C) ±0.5°F (0.3°C)2

0 to 200°F (-17.8 to 93.3°C) Same Same

Instrument Temp. Range Electronics Operation Storage Probe Operation Storage

40 to 113°F (5 to 45°C) -4 to 140°F (-20 to 60°C) 14 to 140°F (-10 to 60°C) -4 to 140°F (-20 to 60°C)

Same -22 to 194°F (-30 to 90°C) 0 to 200°F (17.8 to 93.3°C) -22 to 194°F (-30 to 90°C)

Relative Humidity Range Accuracy

0 to 95% ±3% rh3

N/A N/A

Dew point Range 5 to 120°F (-15 to 49°C) N/A Static/Differential Pressure Range4 Accuracy5

-10.00 to +10.00 inches H2O (-2.500 to +2.500 kPa or -20.00 to +20.00 mm Hg) ±0.5% of rdg ±0.01 in H2O (±0.002 kPa or ±0.02 mm Hg)

Same Same

Volumetric Flow Rate 0.2 to 4,50,000 ft3/min (0.0424 to 1,170,000 m3/hr or 0.1 to 325,000 l/s)

Same

Duct Sizes 1 to 100 inches in increments of 0.5 inch, 100 to 255 inches in increments of 1 inch (1 to 100 cm in increments of 0.5 cm, 100 to 255 cm in increments of 1 cm)

Same

Averaging Capability Up to 255 values each of velocity, temperature, pressure, humidity, or pressure flow

Up to 255 values each of velocity, temperature, pressure, or pressure flow

16 Appendix A

Model 8360/8388 VELOCICALC Plus

(Cont.)

Models 8382/8383 VELOCICALC Plus

(Cont.) Response Time (63% of final value) To Velocity To Temperature

200 milliseconds 8 seconds

Same Same

Time Constant Adjustable from 1 to 20 sec. Same Physical Dimensions External Dimensions Probe Length Weight (with batteries) Display

4.2 in x 7.2 in x 1.5 in (107 mm x 183 mm x 38 mm) 29 in (735 mm) 1.2 lbs (0.54kg) 4-digit LCD, 0.6 in (15 mm) digit height

Same 37 in (940 mm) 1.1 lbs (0.5 kg) Same

Printer Interface Type: Serial BAUD Rate: 1200

Same

Power Four AA-size NiCd rechargeable or Alkaline Batteries (included) or AC adapter

Same

1 Temperature compensated over an air temperature range of 40 to 150°F (5 to 65°C) 2 Accuracy with instrument case at 77°F (25°C). Add uncertainty of 0.05°F/°F (0.03°C/°C) for change in instrument temperature. 3 Accuracy with probe at 77°F (25°C). Add uncertainty of 0.1%rh/°F (0.2%rh/°C) for change in probe temperature. Includes 1% hysteresis. 4 Overpressure range = 300 inches H2O (75 kPa, 560 mm Hg) Specifications within parentheses indicate metric equivalents. 5 Add uncertainy of ±0.02%/°F (±0.03%/°C) for change in instrument temperature.

17

Appendix B DIP Switch Settings To access the DIP switches, remove the batteries from the battery compartment. On the inside of the battery compartment, there is a window with eight DIP switches. The table below shows the functions for each switch. Caution: Make certain that power is turned off before changing DIP switch settings. Switch Function OFF ON

1 Velocity ft/min & ft3/min m/s 2 Flow Rate* l/s m3/hr 3 Pressure in. H2O kPa and mm Hg 4 Pressure** kPa mm Hg 5 Temperature Degrees Fahrenheit (°F) Degrees Celsius (°C) 6 Flow Rate

(8382, 8383, 8388 only)

Flow rate from velocity and area

Flow rate from pressure and flow factor or from veloctiy and area

7 Reserved Reserved 8 Beep Beep Disabled Beep Enabled

- The ON position is away from the batteries and OFF is towards the

batteries. - Always leave DIP switch #7 in the OFF position. * To select flow rate to display l/s or m3/hr, DIP switch #1 must be in the ON position. ** To select Pressure to display kPa or mm Hg, DIP switch #3 must be in the ON position.

18 Appendix B

DIP SWITCH

ON

OFF18

Figure B - 1: DIP Switch Location

19

Appendix C Standard Velocity vs. Actual Velocity

Since thermal air velocity sensors are sensitive to changes in air density and air velocity, all thermal anemometers indicate velocities with reference to a set of standard conditions. For TSI instruments, standard conditions are defined as 70° F (21.1° C) and 14.7 psia (101.4 kPa). Other manufacturers may use different values. Standard velocity is the velocity the air would be moving if the temperature and pressure were at standard conditions. It is usually the most useful measure of airflow because it defines the heat-carrying capacity of the air. Actual velocity is the velocity at which a microscopic particle of dust would be traveling if it were in the air stream. In some instances, actual air velocity rather than standard velocity may be of interest. To obtain the value for actual velocity, multiply your standard velocity by the following density correction factor:

Actual Velocity VT

P=

++

( ).

Standard elocity 460460 70

14 7

Where T = Ambient temperature in degrees Fahrenheit P = Ambient pressure in psia If you use metric units, the equation becomes:

ActualVelocity (Standard elocity) =++

VT

P

m

m

273

273 211

101

.

.4

Where Tm = Ambient temperature in degrees Celsius Pm = Ambient pressure in kPa

20 Appendix C

Example No. 1: You want to measure the actual velocity in a duct. The air temperature in the duct is 55°F and the pressure is 14.24 psia. You take a measurement and the display reads 1200 feet per minute (ft/min).

ActualVelocity =++

=1200460 55460 70

14 714 24

12037..

. ft / min

Example No. 2: You need to measure the actual velocity in a plenum. The air pressure is 99.4 kPa and the temperature is 27°C. The display reading is 2.3 meters per second (m/s).

ActualVelocity 2.3 =++

=273 27273 211

10199

2 39.

.4.4

. /m s